Plane correlations in small colliding systems

I propose event-plane correlations as a test of collectivity in small colliding systems: In d-Au and ${}^3$He-Au collisions, I predict a strong anti-correlation between elliptic and triangular flow, generated by the geometry of the light projectile. A significant anti-correlation is also predicted in central p-Pb collisions at the LHC, which is solely generated by fluctuations. Similar, but stronger correlation patterns are predicted in correlations involving dipolar flow.